2a strip around the edge of something such as a picture or a piece of clotha pillowcase with a lace border

3(in a garden)a strip of soil that is planted with flowers, along the edge of the grassherbaceous borders

4the separation or distance between one thing or person and anotherIt is difficult to define the border between love and friendship.

ThesaurusborderboundaryfrontierbarrierThese are all words for a line that marks the edge of something and separates it from other areas or things.border the line that separates two countries or areas; the land near this line:a national park on the border between Montana and Wyomingboundary a line that marks the edges of an area of land and separates it from other areas:The fence marked the boundary between my property and hers.border or boundary?The point where you cross from one country to another is usually called the border. The line on a map that shows the border of a country can be called the boundary, but “boundary” is not used when you cross from one country to another:After the war, the national boundaries were redrawn.Thousands of immigrants cross the boundary every day.Boundary can also be a physical line between two places, for example between property belonging to two different people, marked by a fence or wall:the boundary fence/wall between the propertiesfrontier the border between two countries or areas; a line that marks the beginning of an unexplored or dangerous area:the frontier between Guatemala and MexicoThe Ingalls family crossed the frontier in a covered wagon.barrier something that exists between two places and prevents easy movement between them:The mountains form a natural barrier between the ocean and the desert.Patternsacross/along/on/over a/the border/boundary/frontier/barrierat the boundary/frontier/barrier the border/boundary/frontier with a place the northern/southern/eastern/western border/boundary/frontier a national/common/disputed border/boundary/frontier